Temperature indication



W. P. DALRYMPLE TBHPERATURE INDICATION Feb. 19, 1929. 1,702,685

Filed Dec. s, 1926 Patented Feb. 19, 1929.

UNITED `sT-A'riszs PATENTg OFI-fics.

WILLIAM r. DALRYMPLE, oF CHICAGO, ILLINOIS.l

TEMBERATURE INDICATION.

Application filed December 3, 19,26. I Serial YNo. 152,441.

mobile engine and thelike; to provide such a device rwhich is suitablefor beingmanufactured in large quantities without requiring accurateadjustments and calibrations; tov provide such a device which ispositive Vin its action, and in which a large movement of theindicatingl member may be. obtained;

and to provide suchla ldevice which isnot materially affected byvibration, and which is not likely to get out of order.

This invention involves the application of a. new principle in thermalindicators' for automobile radiators. When spongy, ab-

sorbent material is exposed to vapors liberated at low temperatures, thevapors condense yin the spongy material,` forming a water plug and ifair is trapped in a confined space above the water plug, then as thetemperature of the vapor increases, the temperature of the plugincreases, but there is no escape for the entrapped air above the plugand the pressure of this airis then available to operate `an indicatoreven where the exciting cause is a free unconiined vapor'below theplug fAn illustrative embodiment of thisv invention is shown in theaccompanying drawings inwhich: y l

.Figure lis anelevation of .the indicator, mounted in a cap yof anautomobile radiator. Fig.2 isay cross section of the indicator. Fig. 3is a. section takenon the line 3-3 ofFig.2." 1:

In this invention, an expansible .element preferably of a lightlfrictionless construction, such asa bellows, is mounted in closedcommunication with a chamber having an inlet which is plugged with anabsorbent material, preferably of a line fibrous composition such asasbestos wool. f

The moisture which isvaporized from the l surface of the liquid, isabsorbed by the plug, and' carried throught() the chamber above theplug, by capillary action. Y. The moisture is condensedbythe coolerwallsof the chamber, so that a small amount of liquidbecomes loosely confinedtherein. When the temperature is raised to the boiling point,

' expanding gases are-rapidly released from the moisture orv liquid,which, causes a pressure in the chamber, which is. restrained by themoisture saturated plug. This pressure is communicated to the interiorof the bellows and causes the bellowsto expand. A suitable` mechanicalsignalling ldeviceis connected to the bellows for operation so that themove- Y .mentof the bellows actua-tes the signalling device. f v

vReferring tothe construction shown in the drawings, a housing isprovided having a cupshaped bottoma and flanged plate 5 which fits overthe top of the portion 4, and a lcover 6 which includesa hood 7forhousing the swinging semaphore member 8.`

A stem, comprising thethreaded tube 9, is sealed in the bottom member 4,and is threaded through a tapped hole in theradi` ator cap 1.0, of theautomobile*radiator.1l. The bellows comprises the upper and lowerflexible cup plates 12 and 13, which are joined at'the edges, formino'in effectan eX- pansible diaphragmcham er.v The lower plate 13 isvbrazed to the upperendrof the vltube 9, and is provided with a hollowstem 111, which opens intothe tube.y rTo provide a condensing pressurechambena coil 15,

,of cop er :wire fabric, is inserted in the upper lend oV .thetube 9,and also serves as a backing for theasbestos wool plug 16, which is heldin place in the lower end ofthe tube by Vmeans of a wire screen 17. y.

The ,semaphore member 8 is pivotally mounted in the housing vandoperativelyconnected tothe` bellows.v lThe semaphore. 8 is centrallypivoted to a lug 18,' which is bent up fromthe material in the covermember 5 and the movement vof the semaphore is limited by kthe endsstrikingthe surface of the plate 5... The connection to the bellows com.prises a looped wire 19 which is secured to thel center of the plate 12,and engages, at the upper-end, ina hole20which is providedin thesemaphore member 8,r quite close to the axis of movement.

-`When the bellows is collapsed, as shown inl Fig. 2, one arm of thesemaphore k8 covers the window 21, in the side wall of the hood 7 and,when the bellows is expanded, the

vsemaphore is rotated to the opposite positionwhere the opposite endcovers theopposite vwindow 22. y f

The-operation ofthe vindicator may be gradual'between wide temperatureor pressure differences, or laccording to the tension on `the loopedspring y,wire 19 and the stops for the indicatorl provided by plate 5,the operation of the indicator may be limited to take place only betweencomparatively close temperature or pressure points. For exam- 5 ple,when the device is used 'for indicating the temperature of some part ofthe cooling system of an automobile., the only function' that may bedesired of the instrument is to indicate an excessively high temperaturel0 upon the failure of thermostatic or other temperature controllingdevicesv of the cooling system to prevent excessive engine temperatures.Assuming that it is desired to have the indicator operate, that is, rockto the right, Fig. 2, only at near the boiling point of the water in theengine aclet, this may be arranged for by the air capacity design andresilience of the bellows formed by the flexible plates 12 and 13andtension on spring 19. The instrument is located at the upper part ofthe radiator and this space is occupied by splashing water, air andvapor, the vapor content of the space increasing according to the risein temperature and, long 'l before the water in the engine jacket isnear the boiling point, vapor condensed in the pervious plug 16, thussealing the air above the plug and in the bellows against escape`downwardly through the plug, when expansion of the air takes placebecause of the rising temperature.

If the device is used in places where there is suflicient steam pressureto cause the steam to pass upwardly through the plug 16, the copperfabric coil 15 which is in metallic contact with a casing of theinstrument then functions 'as a condenser causing moisture to drop downinto the plug 16 and preserve its sealing function.

Vl0 The pressure within the bellows at temperatures very much below theboiling point may, with a certain adjustment of the instrument, beinsuliicient to rock the indicator away from its normal setting as shownin Fig. 2, but when the engine cooling water is boiling, heat is givenoff very rapidly and is conducted to the upper portion of the radiatorand to the instrument itself, thus causing an expansion of the airwithin thebellows suflicient toA operate the indicator.

By the form of thermal motor shown, comprising the bellows and. theplueeed tube 9,

which is substantially the inlet tobthe bellows, a very positive andreliable action is secured for indicating the boiling temperature.Therefore, no adjustment is required, since the semaphore arm 8 ismerely moved from one stopped position to another, and the eX- cessmovement in the motor element is taken4 00 care of by the resilience inthe parts, especially in the looped wire 19.

While but one illustrative embodiment of this invention has been shownand described, many alterations and omissions may be had al!v withoutdeparting from the spirit of the invention as defined in the followingclaims.

lclaim: M p' 1. In an indicator, a thermal motor comprising, a tube, anexpansible chamber mounted on and lenclosing the upper end of said tube,said chamber connected to the interior of the tube, indicating meansresponsive to the expansion of said chamber, a mass of wire fabricinserted in the upper end of the tubo to form a condensing chamber, and7 a plug of asbestos wool in the tube below said mass.

2. An indicator comprising afhousing having a hollow Vstem closed at theupper end, a bellows mounted on the stem and inte-580 riorly connectedtherewith, a semaphore arm pivotally mounted in the housing andconneet-ed to the bellows for operation, and an absorbent plug in thelower end of the tube. n

S. An indicator comprising ahousing hav-S5 ing a hollow'stem mountedinthe radiator cap, an expansible chamber mounted in the housing andcommunicatingwith the interior of said hollow stem, ar signal arm-`movably mounted in the housing vand connected to '39o said expansiblechamber, and an absorbent plug in the lower end of said stem forrestricting the egress of pressure from said eX- pansible chamber. Y

l. The method of indicating the tempera-f ture or pressure of a vaporbearing gaseous medium which consists in trapping a quantity of fluid bythe condensation of moisture from said gaseous medium and utilizing theexpansion orcontractionof said quantity of fluid for indicatingpurposes.

5.111 an indicator, a thermal motor comprising a hollow expansiblechamber, an inlet communicating with said chamber vfor admitting a fluidthereto, and an absorbent plugy vadapted to become saturated withmoisture,

said plug being associated with said inlet'in such relation as torestrain the egress of fluid pressure from said chamber when said plugis substantially saturated.

6. In an indicator, a thermal motor comprising a hollow expansiblechamber, a movable member actuated by the expansion and contraction ofsaid chamber, an inlet kcommunicating with the interior of said chamberlla for admitting fluid thereto and an absorbent plug interposed betweensaid inlettand atmosphere, said plugr when approximately saturatedoperating to substantially seal said inlet against the egress ofpressurey 'from said 120 expansible chamb r. 'l

7. An indicator ol the class described comprising means for forming anenclosed space including a pressure responsive member, a passagewaycommunicating with the interior of said enclosed space and serving toadmit aga'seous fluid thereto, a pervious moisture condensing element insaid passageway adapted to restrain the egress of'lluidpressure fromsaid enclosed space back through said passageway, and indicating meansoperably connected with said pressure responsive member. .f

8. An indicator of the class described comprising means for forming anenclosed space including` a `pressure responsive member, a passagewaycommunicating with the interior of' said enclosed spiace and servingto'adinit air thereto, a mass of absorbent material in said passageway,condensing means lin vsaid passageway adapted to precipitate vaporcondensate on said absorbent material lfor substantially saturating thesaine and thereby restraining the egress of fluid pressure from saidenclosed space back through said passageway, and indicating meansoperably con- A nected with said pressure responsive member.

of said enclosed space and serving to admit a gaseous fluid thereto, apervious moisture condensing element in said passageway v adapted torestrain the egress of fluid pressure from said enclosed space backthrough said passageway, indicating means operably connected with saidpressure responsive member, and restraining means for saidindicatorlimiting its operation to a particularly predetermined change inpressure.

10. A fluid motor comprising an expansible chaniber,'an inlet throughwhich fluid is admitted toY said chamber, and a pervious moistureabsorbing element associated with said inlet and through which saidfluid must densingmeans in said'inlet adapted to precipitate vaporconden sate upon said absorbent plug, said plug adapted .uponsubstantial saturation to restrain counterf'low of fluidpressure throughsaid inlet and thereby serve as a .closurefvalve for said'inlet.

Signed at Chicago this 24th day of November, 1926.

VVILLIAM P. DALRYMPLEV.

